Pathogen associations of Pulex porcinus from wildlife in south Texas

Authors: MAESTAS, SARAH - University Of Texas Rio Grande Valley; Maestas, Lauren

Submitted to: Subtropical Agriculture and Environments
Publication Type: Proceedings
Publication Acceptance Date: 2/27/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Fleas are common parasites of wildlife and domestic animals and several species are associated with the transmission of pathogens causing human and animal disease. Opportunistic collections of fleas from wildlife hosts during research activities in South Texas have resulted in the collection of Pulex porcinus, the javelina flea, from nilgai antelope, black-tailed jackrabbits, coyotes, bobcat, feral swine, and javelina. Pulex porcinus has previously been reported from some of these species, however, nilgai and black-tailed jackrabbits represent new host records. Personal observation indicates that P. porcinus will bite people, and this species has also been detected from domestic dogs. While the ability of this species to transmit common flea-borne pathogens is not known, South Texas is a hotspot for human cases of flea-borne Rickettsia (including Murine-typhus). A total of 63 P. porcinus were screened for Rickettsia and Bartonella spp. (including cat scratch fever) infection. None of the individuals were infected with Rickettsia, but a total of five individuals collected from feral swine were infected with a Bartonella species with high similarity to Bartonella isolated from various wildlife species, including Bartonella species associated with disease in humans and dog-like mammals. These findings indicate the importance of investigating understudied and little known species and a need to further evaluate the relationship of this flea with potential pathogens in rural south Texas.

Technical Abstract: Fleas are common ectoparasites of wildlife and domestic animals and several species are associated with the transmission of pathogens affecting human and animal health. Opportunistic collections of fleas from wildlife hosts during depredation events and research activities in South Texas have resulted in the collection of Pulex porcinus, the javelina flea, from nilgai antelope, black-tailed jackrabbits, coyotes, bobcat, feral swine, and javelina. Pulex porcinus has previously been reported from some of these species, however, nilgai and black-tailed jackrabbits represent new host records. Personal observation indicates that P. porcinus will bite people, and this species has also been detected from domestic dogs. While the vector competence of this species for common flea-borne pathogens is not known, South Texas is a hotspot for human cases of flea-borne Rickettsia. A total of 63 P. porcinus were screened for Rickettsia and Bartonella spp. infection. None of the individuals were infected with Rickettsia, but a total of five individuals collected from feral swine were infected with a Bartonella species with high similarity to Bartonella isolated from various wildlife species, including Bartonella species associated with disease in humans and canids. These findings indicate the importance of investigating understudied and cryptic species and a need to further evaluate the relationship of this flea with potential pathogens in rural south Texas.